Hi wout
You may be thinking of the C-Class with its 25 ft hull length and 14 ft beam plus 300 sq ft wings or larger cat racing classes
http://www.morrellimelvin.com/playstation/index.html Damn -this happens evey time I ask others to propose rules outlines ,

I'll give it a shot and propose some B CLASS basic rules outline .
Just one " I told you so comment " to those that own I-20s and numeous others 20s , the prediction was if the F-20 class concept did not recieve support from sailors and builders it would result in further decline in the numbers of racing sailors and add yet another dead boat class .
Guess what ?
I think the restoration of the B Class may have more universal appeal and hopefully help the cat racing scene .
racing class rules creatingly definingly at your service

Carl